A Well‐Defined Calcium Compound Catalyzes Trimerization of Arylisocyanates into 1,3,5‐Triarylisocyanurates

Abstract

We report the synthesis of a calcium complex (2) bearing a tetradentate monoanionic ligand with a diaminoethane core and phenolate and pyridine peripheral donors. Single crystal X‐ray studies on 2 revealed that LiI was also co‐crystallized, leading to a four‐membered ring with four different elements. 2 was found to be an efficient catalyst for the cyclotrimerization of a variety of aromatic isocyanates under mild conditions.

Lanthanide Mimicking by Magnesium for Oxazolidinone Synthesis

“…In this regard, Pucheault and coworkers developed a tandem dehydrogennation/dehydrocoupling strategy for the construction of alkynylboranes using a magnesium catalyst. Building upon our recent achievements in employing alkaline earth metal compounds for hydrofunctionalization reactions, [23][24][25][26][27][28] we are intrigued by the possibility of using a magnesium compound for intermolecular reactions between isocyanates and propargylic alcohols, and thus providing an efficient pathway for synthesizing oxazolidinone derivatives. A further impetus comes from the works of Hill and coworkers showcasing tandem reactions of alkynes and heterocumulenes to form imidazolidine-2,4-diones using alkaline earth metal amides.…”